Side-by-side comparison of pricing, 12 benchmarks, and generation speed.
| Metric | GPT-5.1 Codex mini (high) | Qwen3.5 35B A3B (Reasoning) |
|---|---|---|
| Input ($/M tokens) | $0.25 | $0.25 |
| Output ($/M tokens) | $2 | $2 |
Verdict. GPT-5.1 Codex mini (high) wins the overall benchmark matchup 1–0 across 1 overlapping categories, but raw benchmark score is only one input to the decision.
Pricing. Both models sit in the budget bracket for output-token pricing. At 1.0× the per-million-token cost, Qwen3.5 35B A3B (Reasoning) is meaningfully cheaper if your traffic is output-heavy (long completions, document generation, agent loops). Qwen3.5 35B A3B (Reasoning) makes more sense when output volume is low and absolute reasoning quality justifies the premium.
Strengths. GPT-5.1 Codex mini (high) is strongest on Intelligence Index (31.3). Qwen3.5 35B A3B (Reasoning) leads on Intelligence Index (29.9).
Speed. Speed data is incomplete for this pair; benchmark and price should decide.
Provider. OpenAI and Alibaba sell to overlapping but distinct developer audiences: OpenAI tends to ship frontier reasoning models with premium positioning, while Alibaba often prices more aggressively. Your existing vendor relationships, billing, and SLA preferences may matter as much as the raw numbers above.
Workload cost. Workload scenarios (per million requests at 30M input + 15M output tokens): GPT-5.1 Codex mini (high) costs $37.50 ($450/year); Qwen3.5 35B A3B (Reasoning) costs $37.50 ($450/year). At a smaller 5M-input/2M-output scale (single-developer tool or prototype): GPT-5.1 Codex mini (high) ≈ $5.25/run, Qwen3.5 35B A3B (Reasoning) ≈ $5.25/run. At agent/realtime scale (200M input / 100M output per million requests): GPT-5.1 Codex mini (high) ≈ $250/run, Qwen3.5 35B A3B (Reasoning) ≈ $250/run.
Recommendation. Both models have legitimate use cases — the right answer depends on whether you are optimizing for benchmark ceiling, latency, or unit cost. Start with the cheaper / faster model, evaluate against your specific task, and only switch if the upgrade shows a meaningful lift.
Head-to-head deltas
Data from Artificial Analysis API — 12 benchmarks
Both models have similar pricing. Check the detailed breakdown above for input vs output token costs.
GPT-5.1 Codex mini (high) wins 1 out of 12 benchmarks compared to 0 for Qwen3.5 35B A3B (Reasoning). See the detailed benchmark chart above for per-category results.
Qwen3.5 35B A3B (Reasoning) generates tokens faster at 151 tok/s vs — tok/s. However, Qwen3.5 35B A3B (Reasoning) has lower time-to-first-token (2.06s vs —s).
Choose based on your priorities: both are similarly priced, GPT-5.1 Codex mini (high) for stronger benchmark performance, and Qwen3.5 35B A3B (Reasoning) for faster generation. For latency-sensitive apps, check the TTFT comparison above.